Autonomic Nervous System Regulation
4.1 Autonomic Nervous System Regulation Introduction
Learning Objectives
- Identify the classifications and actions of autonomic nervous system drugs
- Give examples of when, how, and to whom autonomic nervous system drugs may be administered
- Identify the side effects and special considerations associated with autonomic nervous system drugs
- Include considerations and implications of using autonomic nervous system drugs across the lifespan
- Include evidence-based concepts when using the nursing process and clinical reasoning related to medications that affect the autonomic nervous system
Key Terms
- acetylcholine (ACh)
- adrenergic
- adrenergic agonists
- adrenergic antagonists
- anticholinergics
- autonomic nervous system
- catecholamines
- central nervous system
- cholinergic
- chronotropic
- fight or flight response
- glyconeogenesis
- hemostasis
- hyperglycemia
- inotropic
- involuntary responses
- motor neurons
- muscarinic agonists
- neurons
- nonselective beta blockers
- parasympathomimetics
- peripheral nervous system
- postganglionic neurons
- preganglionic neurons
- selective beta blockers
- sensory neurons
- “SLUDGE”
- somatic nervous system
- sympathetic division
- sympathomimetics
Have you ever wondered what causes your heart to beat or your lungs to breathe? These are examples of involuntary responses the brain controls without the need for conscious thought. The autonomic nervous system (ANS) works using a balance of the sympathetic and parasympathetic nervous systems that regulate the body’s involuntary functions, including heart rate, respiratory rate, digestion, and sweating. Many medications are used to control various cardiovascular, respiratory, and gastrointestinal conditions by acting on ANS receptors. Beta-blockers and anticholinergic medications are the most commonly prescribed medications in this category.
Binds to both nicotinic receptors and muscarinic receptors in the PNS.
Postganglionic neuron where neurotransmitters norepinephrine and epinephrine are released. Includes alpha (α) receptors and beta (β) receptors.
Mimic the effects of the body’s natural SNS stimulation on alpha (α) and beta (β) receptors. Also called sympathomimetics.
Block the effects of the SNS receptors.
Inhibit acetylcholine (ACh) which allows the SNS to dominate. Also called parasympatholytics or muscarinic antagonists. Overall use is to relax smooth muscle.
Controls cardiac and smooth muscle, as well as glandular tissue; associated with involuntary responses.
Include norepinephrine, epinephrine and dopamine. Stimulate the adrenergic receptors.
Anatomical division of the nervous system located within the cranial and vertebral cavities, namely the brain and spinal cord.
Postganglionic neuron where acetylcholine (ACh) is released that stimulates nicotinic receptors and muscarinic receptors. Also relating to drugs that inhibit, enhance, or mimic the action of ACh.
Drugs may change the heart rate and rhythm by affecting the electrical conduction system of the heart and the nerves that influence it, such as by changing the rhythm (increasing) produced by the sinoatrial node. Positive chronotropes increase heart rate; negative chronotropes decrease heart rate.
The response when the SNS is stimulated causing the main effects of increased heart rate; increased blood pressure; and bronchodilation.
The breakdown of glycogen into glucose, causing elevated blood sugar.
The process by which the body temporarily seals a ruptured blood vessel and prevents further loss of blood.
Elevated blood sugar.
Stimulation causes increased force of contraction.
Responses that the brain controls without the need for conscious thought.
Consist of the somatic nervous system that stimulates voluntary movement of muscles, and the autonomic nervous system that controls involuntary responses.
Also called parasympathomimetics. Primarily cause smooth muscle contraction, resulting in decreased HR, bronchoconstriction, increased GI/GU tone, and pupil constriction.
Cells that carry electrical impulses to the synapse of a target organ.
Medications that block both Beta 1 and Beta 2 receptors, thus affecting both the heart and lungs.
Also called muscarinic agonists. Primarily cause smooth muscle contraction, resulting in decreased HR, bronchoconstriction, increased GI/GU tone, and pupil constriction.
An anatomical division of the nervous system that is largely outside the cranial and vertebral cavities, namely all parts except the brain and spinal cord.
Postganglionic neurons of the autonomic system are classified as either cholinergic, meaning that acetylcholine (ACh) is released, or adrenergic, meaning that norepinephrine is released.
All preganglionic neurons (in the SNS and PNS) release acetylcholine (ACh).
Medications that mostly inhibit B1 receptors.
Sense the environment and conduct signals to the brain that become a conscious perception of that stimulus.
Mnemonic for the effects of anticholinergics: Salivation decreased; Lacrimation decreased; Urinary retention; Drowsiness/dizziness; GI upset; Eyes (blurred vision/dry eyes).
Causes contraction of skeletal muscles; associated with voluntary responses.
Associated with the “fight or flight response.” Stimulation causes the main effects of increased heart rate, increased blood pressure via the constriction of blood vessels, and bronchodilation.
Mimic the effects of the body’s natural SNS stimulation of adrenergic receptors. Also called adrenergic agonists.